JPH05180467A - Ice heat accumulator - Google Patents

Abstract

PURPOSE:To provide an ice heat accumulator which can detect ice making amount of flake-shaped ice in an ice making system which utilizes supercooling phenomenon and to improve ice making efficiency, by preventing clogging of a pipe due to freezing of a supercooler and shortening time taken for deposit ice to be melted and removed away. CONSTITUTION:An ice heat accumulator is provided with a supercooler 1 which supercools part of water in a heat reservoir 2 by exchanging heat with brine. A supercooled state of the water which is supercooled by the supercooler 1 is released to crystallize out ice pieces, and the ice pieces are accumulated in a heat reservoir 2. The supercooler 1 is provided with a calorimeter 12 which is formed of a flow rate meter 10 which measures volume of water which circulates through the supercooler 1, a temperature sensing part 9 which senses surpercooling degree of the surpercooled water produced by the supercooler 1, and an operation part 11 which operates ice making amount based on the circulating water volume and the supercooling degree. The supercooler 1 is further provided with a detecting means to detect out the volume or the pressure of the water circulating through the supercooler 1. The detecting means provides signals, according to which a control is made to prevent clogging of a pipe.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ice heat storage device, and more particularly to an ice making system utilizing the supercooling phenomenon of water.
The present invention relates to an ice heat storage device suitable for detecting the amount of ice making by using an electronic calorimeter and preventing blockage in a pipe due to freezing of an ice making device (hereinafter referred to as a supercooler).

[0002]

2. Description of the Related Art In recent years, as the demand for electric power has increased, the difference in the power load between day and night tends to expand, and there is a great need for a heat storage type air conditioning system or the like that is effective as a measure for leveling the power demand. Is being developed. The conventional ice heat storage device is used to deposit ice around the heat transfer tubes in water in the heat storage tank. In this case, the amount of ice making is measured by the volume change in the tank due to the phase change of water (liquid phase → solid phase). Was detected by the water level.

Recently, as an ice making means for storing ice heat, there is ice making using supercooling of water. For example, a technique described in Japanese Patent Laid-Open No. 63-217171 is known.
This technique is to give shock in the process of returning the supercooled water cooled by the supercooler to the heat storage tank to deposit ice pieces (ice particles) and store the sherbet-like ice in the tank. ..

[0004]

In the ice making utilizing supercooling of water, the ice shape is a small flake shape, so that the ice becomes a lump or adheres to the wall surface of the heat storage tank and floats above the water surface. Then, it is difficult to store ice evenly in the tank. Therefore, since the water level changes irregularly, the amount of ice making could not be calculated from the increase of the water level due to ice making.

By the way, in ice making utilizing supercooling of water, the supercooling phenomenon is in an unstable state, and therefore freezing in the pipe of the subcooler may occur due to some factor. When freezing in the pipe occurs, the pipe is closed and ice making stops. Also,
If the inside of the pipe is blocked, there is a problem that the time until the ice is melted in the pipe is thawed until the freeze is released, and thus the ice making operation time for obtaining a predetermined amount of ice cannot be secured.

[0006] The present invention has been made to solve the above problems in the prior art, and provides an ice heat storage device capable of detecting the amount of flake-shaped ice making in an ice making system utilizing a supercooling phenomenon. This is the first purpose. A second object of the present invention is to prevent ice clogging in the pipe due to freezing of the ice making device, i.e., subcooler, and to improve the ice making efficiency by shortening the time until the frozen ice is melted and the ice is completely frozen. It is to provide a heat storage device.

[0007]

In order to achieve the above first object, the structure of the ice heat storage device according to the present invention is a subcooling system in which a part of the water in the heat storage tank is supercooled by heat exchange with brine. In an ice heat storage device for storing ice in a heat storage tank by releasing a supercooled state of the supercooled water by this supercooler to deposit ice pieces, and circulating the supercooler in the supercooler. It is provided with a calorific value measuring means for measuring the amount of water and the degree of supercooling to obtain the calorific value of ice making. More specifically, a flow rate measuring unit that measures the amount of circulating water of the supercooler, and a temperature sensing unit that measures the degree of supercooling of the supercooled water generated by the supercooler,
The supercooler is provided with a heat quantity measuring means composed of an arithmetic unit for calculating an ice making amount from the circulating water amount and the supercooling degree.

In order to achieve the above-mentioned second object, in the structure of the ice heat storage device according to the present invention, the flow rate measuring section of the heat quantity measuring means detects a decrease in flow rate due to freezing in the pipe of the subcooler. And a means for controlling the brine circulation amount based on the detection signal and a means for collecting the brine in the subcooler.

In order to achieve the above second object, another structure of the ice heat storage device according to the present invention is provided with a subcooler for supercooling a part of the water in the heat storage tank by heat exchange with brine. In the ice heat storage device that releases the supercooled state of the supercooled water by this supercooler to precipitate ice pieces, and stores ice in the heat storage tank, in the subcooler, the circulating water pressure of the subcooler is applied. It is provided with a pressure measuring means for measuring and detecting a pressure increase due to freezing in the pipe of the subcooler. Thus, the pressure measuring means detects a pressure increase due to freezing in the pipe of the subcooler, and the ice heat storage device controls the brine circulation amount by the detection signal and the inside of the subcooler. And means for collecting the brine.

That is, the basic principle of the present invention is to employ a method of obtaining the amount of ice making from the amount of circulating water of the subcooler and the degree of subcooling, and to use an electronic calorimeter as a means for that. Further, by utilizing the transmission function of the calorimeter or the pressure sensor, the inside of the pipe is prevented from being blocked when the inside of the supercooler is frozen, and the time for releasing the inside of the pipe is reduced.

[0011]

The electronic calorimeter is composed of a temperature sensing section a, a flow rate measuring section b, and a computing section c, as shown in detail in FIG. The amount of ice making is calculated from the amount of circulating water and the degree of supercooling of circulating water. The calculation formula is as follows.

[Equation 1] G = (Vw / vw · Ts · Cp) / Ri (Equation 1) where G: ice making amount (kg / h) Vw: circulating water amount (l / h) Ts: supercooling degree (° C) Cp: constant pressure specific heat of water (kcal / kg. ° C.) Ri: heat of solidification of water (kcal / kg) vw: specific volume of water (l / kg)

That is, in the calorimeter, the amount of circulating water is multiplied by the degree of supercooling (Vw / vw.Ts.Cp) to obtain the amount of heat of ice making. The amount of ice making heat obtained by the calorimeter is transmitted to the control section of the system, and the amount of ice making G is obtained by dividing by the heat of solidification Ri of water.

If freezing of the subcooler occurs in the supercooler during ice making for some reason, the pipe line decreases due to ice accretion, and the flow rate decreases. Stop the brine circulation pump to stop the freezing process and prevent the inside of the pipe from being blocked. The water to the subcooler continues to circulate, and the ice that has landed on it is thawed. When the ice that has landed has melted and the amount of circulating water has recovered to the specified flow rate, activate the brine cooler and brine circulation pump,
Restart ice making.

If freezing in the pipe of the supercooler occurs due to some factor during ice making, the pressure of the circulating water at the inlet of the subcooler rises due to the decrease of the pipe line due to ice accretion. With this, the same control as described above is performed, and it is possible to prevent in-tube blockage in advance. In particular, if the brine circulation piping system is opened and the brine in the subcooler is collected in the brine cooling tank after the brine circulation pump is stopped, the temperature around the heat transfer tube of the subcooler rises, so that the inside of the tube is frozen. Progress stopped,
It is possible to prevent the inside of the tube from being blocked.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Each embodiment of the present invention will be described below with reference to FIGS. [Embodiment 1] FIG. 1 is a schematic system diagram of an ice heat storage device according to an embodiment of the present invention, FIG. 2 is a block diagram showing an example of an electronic calorimeter adopted in the device of FIG. 1, and FIG. FIG. 4 is a main part configuration diagram showing another example of the flow rate measuring unit of the calorimeter of FIG. 2. Figure 1
In FIG. 1, 1 is a supercooler, 2 is a heat storage tank for ice making, 3 is a brine cooler, 4 is a brine cooler 3 and a supercooler 1
A brine feed pipe connecting 5 to a brine return pipe connecting the subcooler 1 and the brine cooler 3 to each other, 6 a brine circulation pump arranged in the brine feed pipe 4, and 7 a heat storage tank 2.
A cold water pipe connecting 8 to the subcooler 1 is a cold water circulation pump arranged in the cold water pipe 7. In FIG. 1, a piping system that connects the heat storage tank 2 and a load side (for example, an air conditioner) is not shown.

In FIG. 1, 9-1 is a temperature sensing section on the sending side (temperature sensing section a _{1 in} FIG. 2), 9-2 is a temperature sensing section on the return side (temperature sensing section a _{2 in} FIG. ₂ ), and 10 is A flow rate measuring unit (corresponding to the flow rate measuring unit b in FIG. 2) provided in the cold water pipe 7 on the inlet side of the subcooler, 11 is a calculation unit (calculation unit c in FIG. 2), which is an electronic calorimeter 1
Make up 2. Reference numeral 13 is a control unit of this system, and its signal system is shown by a broken line. Reference numeral 14 is an electromagnetic valve provided in the brine circulation system of the subcooler 1, and 15 is a dispersion plate in the heat storage tank 2.

FIG. 2 is a block diagram showing the detailed structure of the electronic calorimeter, particularly the circuit structure of the arithmetic section c. c ₁ is a temperature difference voltage conversion circuit, c ₂ is an operational amplifier circuit, c ₃ is a current switch,
c ₄ is a current frequency conversion circuit, c ₅ is a frequency dividing circuit, and c ₆ is a heat quantity indicating section. As for the electronic calorimeter, for example, the one described in JP-B-53-26832 is known.

As shown in FIG. 3, if the flow rate measuring unit 10 is provided in the bypass pipe 7a of the cold water pipe 7, it is not necessary to increase the pipe diameter of the flow meter even if the system scale increases, and the size is small. It is economical because it can be measured with a calorimeter.

First, the ice making operation performed at night or the like will be described. The brine cooled by the brine cooler 3 is circulated to the subcooler 1 via the brine feed pipe 4 and the brine return pipe 5 by operating the brine circulation pump 6. On the other hand, the cold water in the heat storage tank 2 is operated by operating the cold water circulation pump 8 to cool the cold water pipe 7.
To the subcooler 1 via. Thereby, the circulating water (cold water) from the heat storage tank 2 is continuously cooled by heat exchange with the brine, and supercooled water is generated. The generated supercooled water is discharged from the supercooler 1 to the heat storage tank 2. At this time, the dispersion plate 15 is collided with to give an impact to release the supercooled state,
Ice pieces are precipitated from the supercooled water. Ice pieces and water are heat storage tank 2
It is stored inside. The water in the heat storage tank 2 is circulated to the subcooler 1 again and the above-described process is repeated to make ice.

The heat of ice making is determined by a calorimeter 12.
First, the degree of supercooling of the supercooled water generated by the supercooler ₁ is converted into a voltage by the temperature difference voltage conversion circuit c ₁ and converted into a current by the operational amplifier circuit c ₂ . The flow rate from the flow rate measuring unit 10 is also converted into a current and applied to the current switch c ₃ . The current switch c ₃ operates the current frequency conversion circuit c ₄ for a certain time width, and during this period, the circulating water amount and the supercooling degree are multiplied (Vw / vw · Ts · Cp) to obtain a heat quantity pulse signal (heat quantity of ice making). Be done. Here, in order to detect only the degree of supercooling in the amount of heat exchanged in the subcooler 1,
A resistor with 0 ° C. as a reference is incorporated in the temperature difference voltage conversion circuit c ₁ in the arithmetic unit 11. As a result, the degree of supercooling can be detected as a differential voltage based on the differential voltage with the outlet of the temperature sensing unit.

The heat quantity pulse signal is applied to the frequency dividing circuit c ₅ , and when this reaches the number of pulses corresponding to a predetermined unit heat quantity, one pulse is output and the heat quantity indicating section c ₆ is instructed. The ice-making heat amount obtained by the calorimeter 12 is transmitted to the control unit 13 of the system, and is divided by the heat of solidification (Ri) of water to obtain the ice-making amount shown in (Equation 1).

When freezing in the pipe of the subcooler 1 occurs during ice making due to suction of ice pieces or the like, the pipe line is reduced and the flow rate is also reduced. Accordingly, the brine cooler 3 and the brine circulation pump 6 are stopped by a command from the control unit 13 of the system, the progress of freezing is stopped, and blockage in the pipe is prevented in advance.

Brine cooler 3 and brine circulation pump 6
After the stop, the solenoid valve 14 is opened to open the brine circulation piping system and the brine in the subcooler 1 is collected in a brine cooling tank (not shown). ) The ambient temperature rises, and the time it takes for the ice that has landed to thaw can be shortened in combination with forced convection due to the circulation of water. When the ice accumulated in the pipe is melted and the circulating water amount is restored to a predetermined amount, the electromagnetic valve 14 is closed, the brine cooler 3 and the brine circulating pump 6 are operated, and the ice making is restarted.

According to the present embodiment, by using the calorimeter 12, it is possible to obtain the amount of ice making of flaky ice which has been difficult in the past. In addition, the supercooler 1 due to freezing in the pipe
Since the blockage in the pipe can be prevented in advance and the time until the frozen ice is completely melted can be shortened, the ice making efficiency is improved.

Second Embodiment Next, FIG. 4 is a schematic system diagram of an ice heat storage device according to another embodiment of the present invention. In the figure,
The components having the same reference numerals as those in FIG. 1 are the same as those in the previous embodiment, and therefore the description thereof is omitted. In FIG. 4, 20 is a pressure sensor related to the pressure measuring means provided in the cold water pipe 7 on the inlet side of the subcooler 1, and 21 is a solenoid valve provided in the brine return pipe 5 of the subcooler 1.

When freezing in the pipe of the supercooler 1 occurs due to suction of ice pieces or the like during ice making, the pipe line decreases and the pressure of the circulating water rises. Therefore, the pressure sensor 20 for detecting it.
The brine cooler 3 and the brine circulation pump 6 are stopped in response to a command from the control unit 13 of the system in response to the pressure detection signal to stop the progress of freezing and prevent in-pipe blockage in advance.

Brine cooler 3 and brine circulation pump 6
After the stop, the solenoid valve 21 is opened to open the brine circulation piping system and the brine in the subcooler 1 is collected in a brine cooling tank (not shown). ) The temperature of the surroundings rises, and the time to melt the ice that has landed on ice can be shortened in combination with forced convection due to the circulation of water. When the ice accumulated in the pipe melts and the pressure of the circulating water returns to a predetermined pressure, the electromagnetic valve 21 is closed, the brine cooler 3 and the brine circulation pump 6 are operated, and the ice making is restarted.

According to the embodiment shown in FIG. 4, blockage of the subcooler 1 due to freezing in the pipe can be prevented in advance, and the time until the ice frozen in the pipe is completely melted can be shortened. It is possible to secure an ice-making operation time for obtaining a predetermined amount of ice in 10 hours at night when the price becomes cheap.

[0029]

As described in detail above, according to the present invention, it is possible to provide an ice heat storage device capable of detecting the amount of flake-shaped ice making in an ice making system utilizing the supercooling phenomenon. Further, it is possible to provide an ice heat storage device capable of preventing the blockage in the pipe due to freezing of the ice making device, that is, the supercooling device, and shortening the time until the freezing is released when the iced ice is melted to improve the ice making efficiency.

[Brief description of drawings]

FIG. 1 is a schematic system diagram of an ice heat storage device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an example of an electronic calorimeter used in the apparatus of FIG.

FIG. 3 is a main part configuration diagram showing another example of the flow rate measuring unit of the calorimeter of FIG. 2.

FIG. 4 is a schematic system diagram of an ice heat storage device according to another embodiment of the present invention.

[Explanation of symbols]

 1 Supercooler 2 Heat storage tank 3 Brine cooler 6 Brine circulation pump 7 Cold water pipe 8 Cold water circulation pump 9-1 Sending side temperature sensing part 9-2 Returning side temperature sensing part 10 Flow rate measuring part 11 Calculation part 12 Calorimeter 13 Control Part 14,21 Solenoid valve 20 Pressure sensor

Claims (5)

[Claims] 1. A supercooler for supercooling a part of water in a heat storage tank by heat exchange with brine, wherein the supercooled state of the supercooled water is released by this supercooler to deposit ice pieces,
In an ice heat storage device for storing ice in a heat storage tank, the subcooler is equipped with a heat quantity measuring means for measuring a circulating water amount and a subcooling degree of the subcooler to obtain a heat quantity of ice making. Heat storage device. 2. A supercooler for supercooling a part of the water in the heat storage tank by heat exchange with brine, and releasing the supercooled state of the supercooled water by the supercooler to deposit ice pieces,
In an ice heat storage device that stores ice in a heat storage tank, a flow rate measuring unit that measures the circulating water amount of the supercooler, and a temperature sensing unit that measures the degree of supercooling of the supercooled water generated by the supercooler, An ice heat storage device, wherein the subcooler is provided with a heat quantity measuring unit configured by a calculation unit that calculates an ice making amount from the circulating water amount and a supercooling degree. 3. A flow rate measuring unit of the heat quantity measuring means detects a decrease in flow rate due to freezing in the pipe of the subcooler, and means for controlling the brine circulation amount based on the detection signal and brine in the subcooler. 3. The ice heat storage device according to claim 1, further comprising: means for recovering the ice heat storage device. 4. A subcooler for subcooling a part of the water in the heat storage tank by heat exchange with brine, and releasing the subcooled state of the supercooled water by this subcooler to deposit ice pieces,
In an ice heat storage device for storing ice in a heat storage tank, the subcooler is equipped with pressure measuring means for measuring the pressure of circulating water of the subcooler and detecting a pressure increase due to freezing in the pipe of the subcooler. An ice heat storage device characterized by the above. 5. The pressure measuring means detects a pressure increase due to freezing in the pipe of the subcooler, means for controlling the brine circulation amount by the detection signal, and means for collecting the brine in the subcooler. 5. The ice heat storage device according to claim 4, further comprising: